Forget the atlas, the train schedule, the guidebook, and the local restaurant guide: All you need to travel green in 2011 is your smartphone -- and a few handy apps.
From city guides that let you leave the books behind to calculators that tell you exactly how many offsets you'll need to buy when you get home, these are the seven apps that green travelers shouldn't leave home without.
1. Lonely Planet
A solidly researched, well-written guidebook is an indispensable part of international travel -- just ask the couple spending one day in Paris who didn't know that the Louvre is closed on Tuesdays -- but it can also be a pain to haul around (not to mention the carbon footprint of all that paper and ink).
Lonely Planet apps give you detailed guides to cities all over the world, from Hong Kong and London to Washington D.C. and Barcelona (oh yeah -- and Paris).
It used to be that international travelers needed a handy guide to cab stands and car rental services, but with Velo all you need is an iPhone and your two feet.
The app is designed to help you find bike sharing locations throughout cities including Paris, Brussels, and Luxembourg; green dots show you where bikes are available for pickup, and red ones show you where you can leave the bike you're riding. It's faster and greener than driving, and offers unparalleled ways to see your city.
If you're traveling within the United States, the iTrans app lets you trade expensive, unreliable cabs for trips on the public transportation systems of major cities -- New York, Washington, D.C., Los Angeles, and Chicago (among others).
The app lets you stay up to date with service outages, timetables, and transfers, and even offers walking directions to get you from where you are to where you want to go.
4. Find Green
Formerly 3rd Whale Mobile, the Find Green app has all the same sustainability insights you need when you're on the road, from the closest organic restaurants to the nearest local brewery. And since many of the businesses are submitted -- and rated-- by users, you're really taking advantage of a ton of local knowledge (which is the best kind).
The Live Green tab also includes "crowdsourced sustainable living tips with quantified benefits of how much energy, emissions, water, waste and money you'll save doing them." (Though 3rd Whale says the app is available for the iPhone, we couldn't find it in the iTunes store; however, Find Green did show up in the Android Market.)
5. iLocate Vegan Restuarants
Finding a restaurant that offers something more than chain-spot hamburgers, limp salads, and overpriced pie is hard enough -- finding a vegan restaurant can be even tougher unless you have iLocate Vegan Restaurants on your side.
You can put in your zip code or find nearby restaurants using your GPS -- and then sit back and tuck in for a meat-free meal complete with maps and directions.
You may know what's in season in November in your home state of California, but do you know what you're looking for when you visit your parents for the holidays? And maybe you're an East Coaster who thinks citrus is blooming year-round in Florida -- is that true?
Locavore helps you see what's in season wherever you are, and even helps direct you to the nearest farmers market, for those chefs cooking while on vacation.
Keeping track of your carbon footprint while you're on the road can be tiring -- you end up just guesstimating, and then you buy carbon offsets when you get home (or maybe you just forget).
But with Twavel, you can see just how important those individual choices are: The app lets you total up your travel plans as you you go, and then keeps a running total of your carbon footprint that it compares to other users. Plus, the handy community page lets you set up a carpool or find like-minded walkers in your area.